双酚A双(二苯基)磷酸酯对环氧树脂的阻燃性能

采用双酚A双(二苯基)磷酸酯(BDP)、有机改性蒙脱土(OMMT)和环氧树脂(EP),分别制备了阻燃环氧树脂(BDP-EP)和阻燃纳米材料(BDP-OMMT-EP).利用氧指数、水平垂直燃烧、热重分析以及锥形量热等技术探讨了阻燃材料的阻燃性能和阻燃机理.实验结果证明,BDP-EP和BDP-OMMT-EP的最大热释放速率和平均热释放速率等参数都降低了,但是BDP的阻燃效果优于BDP-OMMT,即BDP和OMMT没有协同阻燃作用.     

核壳型纳米粒子填充PP-EVA及阻燃材料的动态燃烧行为

利用锥形量热仪(CONE)和热重分析(TGA),并结合极限氧指数(LOI)和UL-94垂直燃烧测试方法对核(PSt/OMMT)-壳(PBA)结构纳米复合粒子(CSN)填充聚丙烯(PP)-乙烯-醋酸乙烯酯共聚物(EVA)复合材料及加入无卤复配阻燃剂制备的PP-EVA/CSN/聚磷酸铵(APP)/层状氢氧化镁铝(LDH)复合阻燃材料的阻燃性能及热降解行为进行了研究。结果表明,添加10%(wt)CSN可以提高PP-EVA复合材料的阻燃性能,且PP-EVA复合体系燃烧时的热释放速率、有效燃烧热减少,热稳定性增强。CSN与APP/LDH产生阻燃协同作用,使复合阻燃材料的阻燃性能、热稳定性能进一步提高。     

双层包裹聚磷酸铵微胶囊合成及其在环氧树脂中阻燃研究

采用原位聚合法制备了蜜胺树脂(MF)和环氧树脂(EP)双层包裹聚磷酸铵(APP),得到一种新型核壳结构的微胶囊阻燃剂(EMFAPP).用傅里叶红外光谱(FTIR)和扫描电镜(SEM)对微胶囊的核壳结构进行了表征;用极限氧指数(LOI)、垂直燃烧等级测试(UL 94)对EMFAPP在EP中的阻燃性能进行了研究.EMFAPP在EP基体中阻燃性能优异,当其添加量大于7%时EP/EMFAPP均通过UL 94 V-0级,LOI值达27.0%以上.与未包裹APP相比,EMFAPP耐水性明显提高;经水处理(75℃,6天)后,EMFAPP/EP仍可保持良好的阻燃性能.采用热重分析对EMFAPP及其阻燃复合物的热降解行为进行了研究,EMFAPP能够促进成炭,EP/EMFAPP(8 wt%)在700℃残炭率达16.2%,但其低温稳定性有所下降.此外,利用热失重-红外联用对EMFAPP/EP的热降解行为进行了研究,探讨相关阻燃机理.     

反应型无卤阻燃剂N,N’-双(2-羟乙基)磷酸二乙酯的合成及应用

本文以亚磷酸二乙酯和二乙醇胺为原料合成了一种新型反应型无卤阻燃剂N,N’-双(2-羟乙基)磷酸二乙酯(DEHPA),采用红外光谱、核磁氢谱、核磁碳谱以及核磁磷谱表征了其化学结构。利用DEHPA制备了本质阻燃硬质聚氨酯泡沫材料,通过氧指数(LOI)、水平燃烧测试研究了材料的阻燃性能。同时利用热重分析表征了阻燃剂以及泡沫材料的热稳定性。测试结果表明,当DEHPA以30份替代聚醚多元醇时,聚氨酯硬泡LOI值从19.5%提高到23.6%,通过水平燃烧HB级,继续提高阻燃剂添加量,材料阻燃性能进一步提高。热重分析的结果表明DEHPA可以促进聚氨酯硬泡提前分解并具有优良成炭性能。     

本质阻燃聚苯乙烯/蒙脱土纳米复合物的制备及性能

通过原位聚合法制备了本质阻燃聚苯乙烯[P(St-co-AEPPA)]/有机改性蒙脱土(OMMT)纳米复合物[P(St-co-AEPPA)/OMMT], 并用普通聚苯乙烯/有机改性蒙脱土(PS/OMMT)复合物作为对比实验, 研究了含磷、氮单体丙烯酸羟乙基-苯氧基-二乙基磷酰胺(AEPPA)和OMMT等添加物对本质阻燃聚苯乙烯性能的影响.用X射线衍射仪(XRD)和透射电子显微镜(TEM)分析了复合材料的结构与形貌, 并对OMMT在基体中的分散机理进行了讨论.用差示扫描量热仪(DSC)、热重分析(TGA)和微型量热仪(MCC)研究了材料的热性能和燃烧性能.结果表明, AEPPA和OMMT能够显著提高基体的热稳定性和阻燃性.     

聚磷腈微球的制备及其阻燃PET的研究

采用沉淀聚合法制备聚环三磷腈-co-(3,4-二羟基苯甲酸)(Poly(HCCP-co-PCA))微球,通过傅里叶变换红外光谱、扫描电镜和热重分析等测试手段对其进行表征,研究单体摩尔比对微球的结构、微观形貌以及热稳定性的影响,其中n(HCCP)/n(PCA)为1/0.5时,聚磷腈微球的粒径较为均一,分散均匀,直径为1.5μm左右,并且具有优异的热稳定性和成炭性能。采用熔融共混法制备PET/Poly(HCCP-co-PCA)复合材料,研究Poly(HCCP-co-PCA)的用量对复合材料阻燃性能的影响,并探究其阻燃机理。结果表明,随着Poly(HCCP-co-PCA)含量的增加,复合材料的阻燃性能明显提高。当Poly(HCCP-co-PCA)添加量为1.5(wt)%时,复合材料通过UL 94-V0等级测试,极限氧指数为28.8%,并且热释放速率峰值和总热释放量分别降低了75.26%和69.07%。其阻燃原理主要是燃烧时生成炭层较多,起到较好隔绝效果,同时产生不可燃气体,进一步提升阻燃效果。     

粘胶纤维接枝含磷阻燃单体的研究

用含磷、硫的阻燃共聚单体O,O-二乙基-O-烯丙基硫代磷酸酯与粘胶纤维在四价铈离子作引发剂的条件下,通过自由基共聚的方式制备了含磷、硫的改性粘胶纤维。通过红外光谱(FTIR)、热重分析(TG)、差热分析(DTA)、差示扫描量热分析(DSC)、X射线分析以及扫描电子显微镜(SEM)分析对所制备的改性粘胶纤维进行了表征及性能研究。结果表明,阻燃共聚单体接枝到了粘胶纤维的表面;改性后的粘胶纤维的热分解温度较未改性的粘胶纤维提前,且热性能显著提高。     

无卤阻燃丙烯腈共聚物的制备及性能

以K₂S₂O₈-NaHSO₃ 氧化还原体系为引发剂, 采用水相沉淀自由基聚合法合成丙烯腈(AN)-醋酸乙烯酯(VAc)无规共聚物[P(AN-co-VAc)], 然后在KOH水溶液中进行P(AN-co-VAc)中VAc单元的选择性水解, 再与磷酸和尿素进行磷酰化反应, 制备无卤阻燃丙烯腈共聚物. 用核磁共振氢谱(¹H NMR)、傅里叶变换红外光谱(FTIR)、差示扫描量热(DSC)和热重分析(TGA)对聚合物结构及热性能进行表征, 用凝胶渗透色谱(GPC)测定了P(AN-co-VAc)的分子量及其分布, 并利用FTIR和扫描电子显微镜(SEM)对无卤阻燃丙烯腈共聚物的炭残渣进行分析. 结果表明, VAc与AN发生共聚反应, 制得了P(AN-co-VAc), 随着KOH水溶液pH值的增大, P(AN-co-VAc)中VAc单元迅速水解; DSC分析结果表明, 随着共聚物中VAc单元含量的增大, 共聚物的环化放热分解峰值温度(T_p)增大, 当VAc单元的质量分数为25%时, T_p最大值高达328 ℃, 而阻燃丙烯腈共聚物的T_p高达340 ℃; TGA分析结果表明, 阻燃共聚物在800 ℃时的炭残渣量高达55%以上, 远高于P(AN-co-VAc)的41%, 具有良好的成炭性; 炭残渣的FTIR及SEM结果表明, 阻燃丙烯腈共聚物的阻燃属于凝聚相阻燃.     

含芳基噻唑基团环氧树脂材料的制备及热性能

制备了一种含芳基噻唑基团热稳定环氧树脂材料(TDABZ),通过傅里叶变换红外光谱(FTIR)对其结构进行了表征,采用热重分析-微熵热重分析(TGA-DTG)计算了TDABZ的热分解动力学参数,利用热重分析(TGA)和动态热机械分析(DMTA)探讨了TDABZ的耐热性能。 结果表明,TDABZ通过TGDDM结构中的环氧基团与混合固化剂(DDS和2-ABZ)结构中的活泼氢反应,在较低的温度下就能完全交联固化。 通过Kissinger和Ozawa方法求得TDABZ的热分解活化能分别为205.5和221.9 kJ/mol。 TDABZ固化物具有优异的耐热性能,双悬臂梁法测得的玻璃化转变温度(T_g)达到242.3 ℃,在N₂气气氛下失重5%对应的温度(T_d5)为340.2 ℃,最大失重速率对应的温度(T_dmax)为395.5 ℃,600 ℃的质量保留率为24.1%,显著提高了环氧树脂的热稳定性能,拓宽了其应用领域。     

球形片状微晶碱式碳酸镁的制备、表征及其用作纸填料的特性研究

以六水氯化镁和碳酸钠为原料,乙二醇为介质,采用直接沉淀法制备了碱式碳酸镁纳米粉体。分别用热重分析、X射线衍射、扫描电镜和红外对碱式碳酸镁纳米粉体进行了表征,通过分析确定了其组成和结构。用该法制备出的碱式碳酸镁纳米粉体的平均粒径为35.49nm,呈现球形且由片状微晶组成,分子式为4Mg CO3·Mg(OH)2·4H2O。以球形片状微晶碱式碳酸镁为添加剂制得的纸具有良好的吸水性、吸油性和阻燃性能。     

Enhancement of a hyperbranched charring and foaming agent on flame retardancy of polyamide 6

A hyperbranched polyamine was prepared using an A₂ + B₃ approach. It acted as a hyperbranched charring and foaming agent (HCFA) in combination with ammonium polyphosphate (APP) to form a new intumescent flame retardant (IFR) system for polyamide 6 (PA6). Effect of HCFA on flame retardant and thermal degradation properties of IFR‐PA6 was investigated by limiting oxygen index (LOI), UL‐94 vertical burning, cone calorimeter, and thermogravimetric analysis (TGA) tests. The IFR system presented the most effective flame retardancy in PA6 when the weight ratio of APP to HCFA was 2:1. The LOI value of IFR‐PA6 could reach 36.5 with V‐0 rating when the IFR loading was 30 wt%. Even if the loading decreased to 25 wt%, IFR‐PA6 could still maintain V‐0 rating with an LOI value of 31. TGA curves indicated that APP would interact with both PA6 and HCFA in PA6/APP/HCFA composite under heating. The interaction between APP and HCFA improved the char formation ability of IFR system and then much more char was formed for PA6/APP/HCFA composite than for PA6/APP. Therefore, better flame retardancy was achieved. Moreover, the structure and morphology of char residue were studied by Fourier transform infrared (FTIR), X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The results indicated that compact and foaming char layer containing P‐O‐C structure was formed for PA6/APP/HCFA system during combustion. Copyright © 2010 John Wiley & Sons, Ltd.     

A novel halogen-free flame retardant for glass-fiber-reinforced poly(ethylene terephthalate)

In order to prepare halogen-free flame-retardant glass-fiber-reinforced poly(ethylene terephthalate) (FR-GF-PET), a novel flame retardant containing three flame-retardant elements, P, N and S, was synthesized by melt condensation reaction. Its chemical structure was characterized by FT-IR and ¹H NMR spectra. FR-GF-PET was prepared by melt-mixing the flame retardant with GF-PET. The effects of the flame retardant on the flammability and thermally decomposing behaviors of GF-PET were studied via LOI, UL-94 and TGA tests. The results showed that despite a negative effect on the thermal stability of GF-PET, the incorporation of the flame retardant improved the flame retardancy of GF-PET largely. The LOI values of GF-PET increase linearly with the increase of flame retardant content. The GF-PET passed the V-0 rating in UL-94 tests when 15 wt% of the flame retardant was added to GF-PET. An interesting phenomenon was found, that is, with the increase of flame retardant content, the flame retardancy of the system increased but the char yield decreased, which was explained according to the evidences of XPS tests and the kinetics of thermally decomposing reaction.     

Synergistic effects of aluminum hypophosphite on intumescent flame retardant polypropylene system

The effects of aluminum hypophosphite(AHP) as a synergistic agent on the flame retardancy and thermal degradation behavior of intumescent flame retardant polypropylene composites(PP/IFR) containing ammonium polyphosphate(APP) and triazine charring-foaming agent(CFA) were investigated by limiting oxygen index(LOI), UL-94 measurement, thermogravimetric analysis(TGA), cone calorimeter test(CONE), scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS). It was found that the combination of IFR with AHP exhibited an evident synergistic effect and enhanced the flame retardant efficiency for PP matrix. The specimens with the thickness of 0.8 mm can pass UL-94 V-0 rating and the LOI value reaches 33.5% based on the total loading of flame retardant of 24 wt%, and the optimum mass fraction of AHP/IFR is 1:6. The TGA data revealed that AHP could change the degradation behavior of IFR and PP/IFR system, enhance the thermal stability of the IFR and PP/IFR systems at high temperatures and promote the char residue formation. The CONE results revealed that IFR/AHP blends can efficiently reduce the combustion parameters of PP, such as heat release rate(HRR), total heat release(THR), smoke production rate(SPR) and so on. The morphological structures of char residue demonstrated that AHP is of benefit to the formation of a more compact and homogeneous char layer on the materials surface during burning. The analysis of XPS indicates that AHP may promote the formation of sufficient char on the materials surface and improve the flame retardant properties.     

A novel efficient halogen-free flame retardant system for polycarbonate

A novel silicon- and phosphorus-containing flame retardant, poly (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide siloxane), P(DOPO-VTES) was synthesized from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO) and vinyltriethoxy silane(VTES). Its chemical structure was confirmed by FTIR. The thermal gravimetrical analysis (TGA) showed that P(DOPO-VTES) had good thermal stability and a high of char yield (86.31%) at 700 °C in nitrogen atmosphere. Its XRD patterns showed that this compound had a certain ordered structure. P(DOPO-VTES) was blended with polycarbonate (PC) together with montmorillonite(MMT) to prepare a series of organic-inorganic hybrids of flame retardant (PC)/P(DOPO-VTES)/MMT via melt blending. The thermal degradation behavior and flame retardancy of those hybrids were investigated with TGA, limiting oxygen index (LOI), vertical burning test (UL-94), and cone calorimeter. The LOI value of the flame-retardant PC systems could reach a maximal value of 32.8 when the content of P(DOPO-VTES) was 5 wt%. When 2 wt% MMT was added into the PC/5%P(DOPO-VTES) system, the UL-94 rating reached V-0. The possible flame retardant mode of MMT was studied via the dynamic rheological properties of the systems and the morphology of the chars remaining after the LOI test and the cone calorimeter test.     

聚磷酸酯阻燃剂复配聚磷酸铵对环氧树脂阻燃性能的影响

合成了一种9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)的衍生物——聚苯氧基磷酸-2-10-氢-9-氧杂-磷杂菲基对苯二酚酯(POPP), 以间苯二胺(m-PDA)为固化剂, 环氧树脂(EP)为基料, POPP为阻燃剂, 复配聚磷酸铵(APP), 制备了不同磷含量的阻燃环氧树脂. 利用极限氧指数(LOI)和垂直燃烧(UL94)实验表征了环氧树脂的阻燃性能; 以热重分析、 锥型量热和扫描电镜分析了阻燃环氧树脂的热性能和表面形态. 研究结果表明, 阻燃剂总加入量(质量分数)为5%时即可达到UL94 V-0级, 同时LOI值为27.7%; 当总加入量为15%, 即w_POPP=5%, w_APP=10 %时, 其LOI值可达到33.8%. 随着磷含量的增加, 阻燃环氧树脂的初始降解温度略有降低, 但高温下的残炭率明显增加. POPP/APP的加入在很大程度上降低了环氧树脂的热释放速率、 有效燃烧热、 烟释放量和有毒气体释放量. 阻燃环氧树脂在高温下形成比较稳定的致密膨胀炭层, 为底层的环氧树脂主体隔绝了分解产物及热量和氧气交换, 增强了高温下的热稳定性.     

Synergistic Effect of Novel Synergists–Transition Metal Ion-incorporated Nickel Phosphates with Intumescent Flame Retardants in Polypropylene

The two kinds of transition metal ion-incorporated nickel phosphates (TMIVSB-1) were synthesized by the hydrothermal method. The flame retardancy and thermal behavior of intumescent flame retardants (IFR), with and without TMIVSB-1 for PP, were investigated by LOI, UL-94 test, thermogravimetric analyses (TGA) and cone calorimetry. TMIVSB-1 can obviously improve the flame retardant behavior of IFR systems according to the results of LOI values and UL-94 test. The results of LOI show that 2 wt% TMIVSB-1 can increase the LOI value by 3–5 unit compared with that of PP/IFR composite. The UL-94 test shows that PP with 20% IFR burns and has no rating, but the addition of a small content 2 wt% of TMIVSB-1 with 18 wt% of IFR can reach a UL-94 V-0 rating. TGA results show that the thermal stability of PP/IFR/TMIVSB-1 increases obviously more than that of PP/IFR when the temperature is above 265°C. From cone calorimetry results, it can be observed that the HRR peaks are not obviously decreased, but the burning time of PP/IFR/FeVSB-1 (351s) and PP/IFR/ZnVSB-1 (380s) is obviously prolonged compared with that of PP/IFR (303s). The real time FTIR spectra (RTFTIR) demonstrates that the addition of TMIVSB-1 further staves the decomposition of the PP composites. The scanning electron microscopy (SEM) indicates the quality of char forming of PP/IFR/ TMIVSB-1 is superior to that of PP/IFR.     

Combustion properties and thermal degradation behavior of polylactide with an effective intumescent flame retardant

An intumescent flame retardant spirocyclic pentaerythritol bisphosphorate disphosphoryl melamine (SPDPM) has been synthesized and its structure was characterized by Fourier transformed infrared spectrometry (FTIR), ¹H and ³¹P nuclear magnetic resonances (NMR). A series of polylactide (PLA)-based flame retardant composites containing SPDPM were prepared by melt blending method. The combustion properties of PLA/SPDPM composites were evaluated through UL-94, limiting oxygen index (LOI) tests and microscale combustion calorimetry (MCC) experiments. It is found that SPDPM integrating acid, char and gas sources significantly improved the flame retardancy and anti-dripping performance of PLA. When 25 wt% flame retardant was added, the composites achieved UL-94 V0, and the LOI value was increased to 38. Thermogravimetric analysis (TGA) showed that the weight loss rate of PLA was decreased by introduction of SPDPM. In addition, the thermal degradation process and possible flame retardant mechanism of PLA composites with SPDPM were analyzed by in situ FTIR.     

Co-microencapsulation of biomass-based char source and melamine polyphosphate and investigation for their synergistic action in flame-retarding polypropylene

In this article, co-microencapsulation technology was utilized for decorating the surface of dialdehyde starch (DAS) and melamine polyphosphate (MPP) via one-step process. The aim for this design was to improve the dispersion for DAS and MPP in polypropylene (PP) and employ DAS as sustainable char-forming agent, which lied in enhancing the flame retardancy of PP. In view of chemical composition, morphology and surface wettability, the changes for DAS and MPP after modification were confirmed by energy dispersive spectrometer (EDS), scanning electron microscope (SEM) and water contact angle (WCA) tests, respectively. Most of all, the results for flame retardant tests demonstrated limiting oxygen index (LOI) value and vertical burning tests (UL-94) rating of PP/30 ph M[M&D] were 28.2% and V-1. Along with the synergistic effect, the homogeneous dispersion of DAS and MPP in PP after co-microencapsulation modification was also one of main reasons for the increased flame retardant properties. Except that, the chemical interaction between DAS and MPP in producing the char layer was also certified by TGA curves. After systematic analysis on char residue, the possible intumescent flame retardant mechanism was primarily proposed.     

Inherent flame retardation of bio-based poly(lactic acid) by incorporating phosphorus linked pendent group into the backbone

The molecular design for inherently flame-retardant poly(lactic acid) (IFR-PLA) was outlined and achieved by chemically incorporating an effective organophophorus-type flame retardant (FR) into the PLA backbone via the chain extension of the dihydroxyl-terminated prepolymer with 1, 6-hexamethylene diisocyanate (HDI). The structure of IFR-PLA was characterized by ¹H- and ³¹P-nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy. IFR-PLA was further blended with the commercial PLA to prepare flame retardant PLA blends (PLA-FR blend). The relevant properties of IFR-PLA and PLA-FR blends were evaluated by differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), limiting oxygen index (LOI) measurements and UL-94 tests. The thermal analysis revealed that the char yield of IFR-PLA and PLA-FR blend above 400 °C was greatly enhanced compared to that of pure PLA. The LOI value was significantly improved from 19 for pure PLA to 29 when 1 wt% of phosphorus content was introduced and all IFR-PLA samples achieved V-0 rating in the UL-94 tests. PLA-FR blends had an LOI value of 25-26 and UL-94 V-2 rating at 20 wt% of IFR-PLA content. The tensile strength of all the FR PLA systems was ca. 60 MPa. The method used in this study provided a novel route to permanently flame retard PLA.     

Synergistic effect of boron containing substances on flame retardancy and thermal stability of intumescent polypropylene composites

The synergistic effect of four different boron containing substances, zinc borate (ZnB), borophosphate (BPO₄), boron silicon containing preceramic oligomer (BSi) and lanthanum borate (LaB), were studied to improve the flame retardancy of a polypropylene (PP) intumescent system composed of ammonium polyphosphate (APP) and pentaerythritol (PER). The flame retardancy of PP composites was investigated by limiting oxygen index (LOI), UL-94 standard, thermogravimetric analysis (TGA) and cone calorimeter tests. The addition of 20 wt% intumescent flame retardant (IFR) improves the flame retardancy by increasing the char formation. According to LOI and UL-94 test, boron compounds show their highest synergistic effect at 1 wt% loading. BPO₄ containing composite shows the highest LOI (30), lowest maximum heat release rate (HRR) and lowest total heat release rate (THR) value. Although the char yield increases as the amount of boron compounds increases, the flame retarding effect decreases. Cone calorimeter and TGA data indicate that the boron compounds are likely to show their synergistic effect by reinforcing the integrity of char which improves its barrier effect rather than increasing the char yield.